Rust bindings to libaom

By default, this crate uses cmake to build libaom, and links it statically.

To link dynamically to an existing build instead, set env variables: LIB_AOM_STATIC_LIB_PATH, LIB_AOM_INCLUDE_PATH, LIB_AOM_PKG_CONFIG_PATH.

lib.rs:

These are automatically generated C bindings for libaom